Illuminating device



Filed May' 14, 1929 2 Sheets-Sheet 1 i K INVENTOR BY A m 1-. j g, AORNEYS Nov. 28, T933. R. HOWE 1,936,762

ILLUMINATING DEVICE Filed May 14, 1929 2 Sheets-Sheet 2 INVENTORPatented Nov. 28, 1933 UNITED STATES PATENT OFFICE 14 Claims.

This invention relates to illuminating devices and with particularity tohigh powered lamps.

The invention has for its principal object to provide a high poweredlamp which is capable of '5 carrying very large currents withoutdeterioration of the elements and-supports within the lamp.

Another object of the invention'is to provide a high poweredlamp whichis suitable for photographic purposes, or for any purpose where light ofgreat intensity is required.

While lamps of the glowing filament type have been used for a number of,years for photography, signaling, etc. it has been found that because ofthe structure, weight and arrangement of the filament, together with thefact that the filament must necessarily be operated at an extremely hightemperature, great care must beexercised in the manner of supporting theglowing elements.

Accordingly it isone of. the principal features of this invention toprovide anovel method of supporting a concentrated coiled filamentwithin an evacuated container or envelope, whereby the excessivetemperatures of the glowing element exert substantially no deleteriouseffect on either the lead-in wires or the filament supports.

Another feature of the invention resides in the manner of bracing thefilament supports of a high powered lamp in such a way that the weightof the filament and-associated parts is incapable of bending or breakingsaid supports while the lamp is being operated at high temperatures.-

A further feature pertains to the manner of supporting a concentratedfilament having substantial weight, within an evacuated container,whereby the filament is enabled to expand and contract within very widelimits, without destroying any of the filament supports.

A further feature of the invention resides in a high powered lamp of theglowing filament type, wherein the filament may be supported within thelamp with a minimum of joints in the supporting elements.

A still further feature pertains to a base for a high powered lamp,which base is capable of selfadjustment without breakage, in accordancewith I the expansions and contractions of the lamp envelope.

I, Another feature pertains to the organization ,and arrangement ofelements which go to make up a high efliciency, high power lamp, whichis of maximum durability and is free from breakl age, due either to thehigh temperatures at which the lamp operates, or due to vibration duringhandling, shipping, etc.

Referring to the drawings;

Fig. 1 shows a front view of a high powered lamp constructed accordingto the invention, 0 witha portion of the envelope broken away;

Fig. 2 is a side View of the lamp shown in Fig. 1, with the enveloperemoved;

Fig. 3 is a View showing the arrangement of the lead-in wires; I I IFig. 4 is a detail view of the manner of uniting the filament supports;

Figs. 5 and 6 are detail views showing th manner in which the filamentis supported at the top; I

' Figs. 7 and 8 are detail views of the manner of supporting the lowerend of the filament;

Figs. 9 and 10 show a modified manner of supporting the top part of thefilament;

Fig. 11 shows a modified manner of mounting and anchoring thefilamentsupporting block;

Fig. 12 illustrates another way in which the filament I supports may bebraced with each other.

Referring more particularly to Figs. 1, 2 and 3, the numeral 1represents an evacuated envelope which may be of any well known shape,but is preferably so formed that the portion containing the glowingelectrode 2 is spherical in shape and sufiiciently large with respect tothe filament, to prevent the temperature of the filament destroying ordeteriorating the envelope wall. For this purpose it is preferred toform the envelope 1 out of pyrex glass or any other highlyrefractorytransparent medium. The lower portion 3 of the envelope issubstantially cylindrical and constricted, and is provided with areentrant portion 4, having projections 5, 6, 7 and 8 formed integrallytherewith, and within which are sealed the flead-in and filament supportwires 9, 10, l1 and 12, While any well known manner of sealingin thelead wires may be employed, it is preferred to use lead-in'wires of amaterial having substantially the same coefiicient of expansion as thematerial of the envelope 1, or of the projections 5, 6, 7 andS. It hasbeen found that tungsten rods or wires serve particularly well for thispurpose.

As represented in Figs. 1 and 2, the filament supports are arranged intwo lateralsets 9, 11 and 10, 12, respectively and the rods of each set,for example, rods 9 and 11 are bowed outwardly from each other and crosseach other at, or near the point 13, as shown more clearly in Fig. 2. Atthe point of crossing, these rods may be integrally united by a weld oreven permanently fastened together by means of an additional piece ofwire, or any other equivalent fastening means or they may be eventwisted around each other. As shown in Fig. 2, each set of rods, forexample the left hand set 9 and 11, after crossing, diverge from eachother, and are continued upwardly as shown, into the spherical portionof the envelope, and then converge between each other and cross at thepoint 14. I

As shown more clearly in Fig. 4, one of the rods of each set, forexample the rod 11, has a portion 16 bent at substantially right angles,and continues into the filament support block 15. The end of theassociated rod 9 at the point of crossing 14, is welded to the rod 11and terminated at the weld. If desired, the end of the rod 9 may begiven one or more turns around the rod 11, as shown in Fig. 4, prior towelding, or if desired, reliance may be placed entirely upon thetwisting of the rods to prevent displacement. The right hand set of rods10 and 12 are extended upwardly from the press projections 8 and 8 in asimilar manner to the rods 9 and 11. Thus as shown in Fig. 4, the rod 12continues on into the block 15, while the associated rod 10 is twistedaround the rod 12 at the point of crossing, and may be welded thereto asdescribed in connection with rods 9 and 11. The block 15 is of anysuitable highly refractory and insulating material. It has been foundthat zirconia serves particularly well for this purpose because of theexexcessive temperatures encountered in the lamp when in operation. Theends 16 and 1'? of the wires 11 and 12 respectively, are fused into theends of the block 15in any convenient manner, in order that a rigidjoint may be provided with the block. It is preferred to provide theportions 16 and 17 of the rods with enlarged ends 18 and 19 (Fig. 5)which may be positioned within the block 15 when the same is in asemi-molten condition. 7

Each set of rods 9, 11 and 10, 12 are rigidly spaced at their bowedportions by means of the bridge members 20, 21, which are preferablyformed of tungsten and welded to the associated rods. If desired theends of the bridge members may be given one or more turns around thefilament supports prior to welding.

The above described arrangement provides two lateral and parallelsupporting frames which are rigidly united at their upper end by meansof the insulating block 15. Disposed between the opposite frames is thefilament 2, which is preferably of coiled tungsten and formed into theshape shown in Fig. 1. While this figure shows the filament as made upof four serially connected coil sections, it will be understood that anynumber of sections may be employed, and these sections may be connectedin parallel if desired.

In order that the filament may be centrally located and supportedbetween the frame members, the ends of the two central coiled sections22 and 23 are bent upwardly to provide a loop 24, and similar loops 25and 26 are provided at the lower ends of the coiled sections. As shownmore clearly in Fig. 2, the opposite ends 2'7 and 28 of the spirallyconnected coils are bent at right angles to the coils, and are extendedto the bridge members 20 around which they are twisted and welded, ifdesired.

' For the purpose of supporting the central sections, the block 15 haswrapped around its central portion a metal strap 29 which, as shown indetail in Fig. 6, has its free ends formed in hook fashion, and with oneend 30 overlapping the other end 31 to prevent the ends from separating,due to the high temperatures at which the lamp is operated. The hookportion of the strip 29 engages the loop 24 of the filament and providesa strong support therefor. The purpose of making the member 29 ofrelatively wide strip material is to distribute the weight of thefilament material over as large an area of the block 15 as possible,since it has been found that where the filament is supported merely by arod or wire extending around the block that the said block, because ofthe high temperature, has a tendency to crack at the point of support.

Similarly for the purpose of anchoring the lower end of the filamentthere is provided a block of insulation 32, which is preferably ofzirconia or similar refractory material, and this block is supported onthe bridge members 21 by means of the laterally extending rods 33 and34, which are fused at one end into the block 32 and at the opposite endare welded onto the bridge members 21.

As shown more clearly in Figs. 7 and 8, a strip of metal 38 is formedaround one end of block 32, and has its free ends 36 and 37 curved tothe shape shown in Fig. 8, and overlapping. A similar strip of metal isprovided at the other end of the block 32. The loops 25 and 26 areslipped in between the overlapped edges of the strips 35 and 38respectively, and thus allow the filament to expand and contract withoutpermitting the filament to come in contact with the main supportingframework.

For the purpose of properly supporting the assembled lamp, there isprovided a base 39 (Figs.

1 and 2) which may be of pressed steel, brass or other suitablematerial. The lower portion of the base which receives the end of thelamp is cup-shaped, and is provided on opposite sides with discs ofinsulating material 40 and 41, which may be of asbestos, asbestos boardor similar heat resisting material. Each of the discs is provided with aset of four holes which register with corresponding holes in the bottom42 of the base, and the discs are clamped to the bottom 42 by suitablebolts 43 and nuts 44 on opposite sides thereof. The unthreaded portionsof the bolts 43 extend downwardly and provide contact prongs whereby thelamp may be inserted in a $23 suitable receptacle. Flexible copper leads51 are then fastened to the upper ends of the members 43 and connectedto the rods 5, 6, 7 and 8, where they emerge from the pressed portion.

As shown in Figs. 1 and 2 the bottom as of 138 the base is provided withan upwardly extending portion 45 which terminates in a split ringportion 46, which also surrounds the constricted portion of the lamp.The ends of the split ring portion overlap each other, and thus providea semi-resilient support for the lamp, enabling the lamp to tilt ineither direction or to expand without damage to the envelope. If desiredthe overlapping ends of the ring portion 46 may be provided withcooperating lugs to prevent disen- A! gagement thereof due to excessmovement of the lamp in the base. A layer of asbestos or other similarpacking is provided between the metal parts of the base and the glass asindicated by numeral 52.

From the foregoing it will be seen that there is provided a lampstructure which is capable of being operated at exceedingly hightemperatures, and that the filament is supported with a p truss-likestructure, and that the main portion of this structure is removed fromthe destructive temperature field of the filament. Furthermore each legof the filament support is throughout its length, formed from the samematerial, and the only joints required are where the ends 16 and 17(Figs. 4 and'5) are united to the block 15.

Thus a continuous piece of material is used for the seal-in and filamentsupports, obviating the use of welds'which have been found to be subjectto a great deal of breakage due to the temperature and weight of theglowing filament.

Referring to Figs. 9 and 10 there is shown a modified manner ofsupporting the filament on the block 15. In this embodiment the block 15is provided with an opening 4'? through which passes the filamentsupporting hook 53. The upper surface of block 15 is provided with ametal cap 48 to which the hook 53 is united, preferably by welding, andindicated by the numeral 49.

Fig. 11 shows another manner of supporting the lower block 32 on theframe members. In this embodiment the bridge members 21 may be dispensedwith and the projections 33 and 34 may connect with diagonally oppositelegs is and 11 of the framework. In order that the block may bepositioned centrally within the filament supporting frame, the rods 33are preferably fashioned in the shape shown in Fig. 11, although anyother manner of centrally supporting the block may be employed.

Fig. 12 shows a modified manner of forming the side frame members. Inthis embodiment the legs 9 and 11 for example, instead of crossing attheir lower ends may be crossed at their middle portions, and partiallytwisted around each other, as indicated by the numeral 50, where theymay be welded if desired.

While specific structures and apparatus have been disclosed in theforegoing, it will be understood that the invention is not limitedthereto, and that changes may be made therein without departing from thespirit and scope of the invention.

What is claimed is:

1. In an illuminating device an evacuated envelope having a reentrantbase, a luminous element within said envelope, and means for supportingsaid element, including a plurality of rod sets of highly refractorymaterial each rod supported at one end in the base, said rods of eachset converging towards each other within the envelope, and being rigidlyfastened together at the point of convergence, said rods also serving aslead-in conductors.

2. In an illuminating device having an envelope with a base portion, afilament, and two sets of supports for supporting said filament each setincluding a pair of rods united at opposite 'ends, and bowed outwardlyand crossing each other intermediate said ends, the lower ends of saidcrossed rods being sealed into said base.

8. An illuminating device according to claim 2, in which the filament issupported at its center from said supporting means between the bowedportions thereof.

4. In an illuminating device an evacuated container having a baseportion, a filament and means for supporting said filament comprising arod supported at one end in the base of said envelope, and another rodsupported at one end at a different point in said base, both of saidrods converging towards each other, and being united at a plurality ofpoints throughout their length.

5. In an illuminating device, the combination of an evacuated envelope,a filament, a plurality of frame members for supporting said filament,each comprising a set of rods extending upwardly from the baseof saidenvelope, the rods of each set being united at their upper ends and at apoint intermediate their ends, the rods diverging from each otherintermediate the points of union, a tie member niting the rods of eachset at the said diverging portions thereof, said filament beingsupported from said tie members.

6. In an illuminating device of the glowing filament type, means forsupporting the filament for free expansion in all directions, comprisingtwo laterally disposed frames, each frame comprising a plurality of rodsunited at separated points and bowed outwardly from each otherintermediate the points of union, one rod of each frame having one endbent at right angles to the main body portion thereof, and a refractoryinsulator block rigidly uniting the said bent ends.

'7. In an illuminating device having an envelope with a reentrant baseportion, a coiled filament and means for supporting said filament atmore than two points in said base, and comprising two sets of rods, therods of each set being welded to each other at points near the endsthereof, and separated from each other throughout their lengthintermediate said welds, the lower ends of said rods being sealed intosaid base.

8. In an illuminating device having an envelope with a base portion, acoiled rod filament, means for supporting said filament at three or morepoints in said base, and comprising two sets of rods, the rods of eachset crossing and welded to each other at a point sufliciently farremoved from the filament to prevent the weld being destroyed by thefilament heat, a block of refractory insulating material rigidly unitingthe ends of said rods, and a filament suspension member carried by saidblock.

9. In an illuminating device a filament in the form of connected coilsections, a filament support frame comprising a plurality of sets ofrods, the rods of each set being united by a tie member, an insulatingblock rigidly uniting the ends of each set of rods, means carried bysaid block for supporting the central sections of the filament and meansfor supporting the endsections of the filament on the oppositelydisposed tie members.

10. A filament support for incandescent lamps comprising a block ofrefractory insulating material, a metal strap passing around said block,the free ends of said strap being formed in hook shape, and overlappingeach other, a plurality of 130 pairs of rods to which said block isattached, the lower ends of said rods forming a four-point support forthe filament assembly.

11. In a high powered incandescent lamp, a filament composed of aplurality of adjacent 135 coiled sections, a plurality of filamentsupport frames, and a block of refractory insulating material betweensaid frame members at opposite ends thereof, each of said framescomprising a pair of crossed wire rods welded to each other 145 at theirpoint of crossing.

12. In an incandescent lamp, a filament, filament support frameslaterally disposed with respect to said filament, said frames beingunited at opposite ends by refractory insulating blocks, 345 a strapsurrounding the upper block and having a hooked portion for engaging thefilament, a plurality of spaced straps surrounding the lower block, eachhaving a portion for engaging the filament and retaining it centrallybetween said 150 insulating block uniting the upper ends of each frameand on which a portion of the filament is supported, another insulatingblock for guiding the lower portion of the filament and centrallymounted between said frames.

14. An incandescent lamp according .to claim 13 wherein said other blockis supported from diagonally opposite frame-rods.

RAYMOND HOWE.

